In 1926 the Bronx Zoo exhibited some captured “dragons” (250-pound carnivorous Komodo dragons), which Lovecraft and his circle went along to see…
From Wonders of Animal Life, circa 1930s.
Interestingly, the dragon exhibition also directly inspired King Kong…
From: King Kong: the history of a movie icon from Fay Wray to Peter Jackson, by Ray Morton.
They don’t seem to have directly inspired Lovecraft, unless perhaps you count the description of Cthulhu…
“a scaly, rubbery-looking body, prodigious claws on hind and fore feet” — “The Call of Cthulhu”.
Lovecraft may also have seen evocative photos of their habitat in the magazines…
“Ugly roots and malignant hanging nooses of Spanish moss beset them, and now and then a pile of dank stones or fragment of a rotting wall intensified by its hint of morbid habitation a depression which every malformed tree and every fungous islet combined to create.” — “The Call of Cthulhu”.